National Gallery Technical Bulletin Volume 13, 1989

Paint Media Analyses

John Mills and Raymond White

Notes to the Table

1. These samples were examined by gas-chromatography only and although reported in (note 1), they are included here for completeness.
2. The use of two different oils, here, seems fairly certain in view of the pronounced difference in palmitate/stearate ratios.
3. Alkyd medium (an oil-modified alkyd), established in sample 1, is a synthetic medium and its use here corresponds with an area of paint from an added section to the painting. The presence of alkyd in this sample was established by the appearance of dimethyl phthalates (m/z = 194(M+); m/z = 163(B+)) in the chromatogram, following the saponification and methylation. Sample 2 was taken from the interfacial region between the two and almost certainly represented retouching at the divide between the two areas.
4. The nonanedioic to octanedioic ester ratio of 2.73 in the white impasto (sample 1) would suggest the use of a heat-bodied linseed oil (note 2, 3), whereas the yellow impasto gave no indication of such pre-polymerization. This may account for the noticeably differing behaviours whilst sampling. The white impasto yielded in a plastic manner, whereas the yellow impasto was hard and brittle, clearly bodied by a high proportion of pigment and did not show a low (C9/C8) dicarboxylic ester ratio.
5. Examined by gas-chromatography only and reported earlier (note 4), but included here for completeness.
6. Paint from the brown background (sample 2) exhibited an intermediate azelaic to palmitic ester ratio and would correspond to a mixture of drying oil and egg tempera. However, it is not entirely certain that some retouching from adjacent areas was not accidentally included during sampling.
7. Sample 2, of black background, was taken from an area which contained no visible retouching. Linseed oil was identified as well as a diterpenoid resin component. Somewhat unusual was the absence of dehydroabietic acid ester in the chromatogram, the main resin component having molecular ion of ‘m\z’ = 312 and base peak of m/z – 237, suggesting dehydrodehydroabietic ester. Nevertheless a conifer source is still indicated for the resin.
8. The sample of rich, white impasto (sample 1) sampled in a similar manner to that of the white impasto from No.6350, above. Again a C9/C8 dicarboxylic ester ratio of 2.69 may be indicative of heat pre-polymerization of the linseed oil. The red impasto (sample 2), however, sampled in a more brittle manner and the corresponding ratio gave no evidence for the use of heat-bodied linseed oil.
9. Examined by gas-chromatography only, but not previously reported other than in outline (note 5). In view of the presence of both linseed and walnut oils in this work, the P/S ratio of 2.1 for sample 2 may represent linseed with some walnut oil added.
10. All samples from No.727, save paint from the pale blue sky alone, appear to consist of predominantly egg tempera mixed with a little drying.oil. Interestingly, the somewhat richer-textured red paint of sample 4 was found to contain a greater proportion of drying oil than the other paints sampled in this work.
11. This work exhibited areas of pronounced blanching of the paint, particularly in the greens. It was possible to sample from one such area, and the result is recorded in the entry for sample 4. The P/S ratio of 1.4 and the azelate/palmitate (A/P) ratio of 1.1 is perfectly normal for a typical linseed oil medium. However, considering the sample size, it was clear that the paint has become very lean in medium. No resin, either di- or triterpenoid, was detected. It may well be that depletion of the organic medium between the mineral pigment particles has left voids, so enhancing light scattering.
The reddish ground in this picture was also found to contain linseed oil, but seemed very lean in organic medium.

References
1. Mills, J. S. and White, R., 'Analyses of Paint Media', ‘National Gallery Technical Bulletin’, 4 (1980), p.67.
2. Mills, J.S. and White, R., 'Organic Mass-Spectrometry of Art Materials: Work in Progress', ‘National Gallery Technical Bulletin’, 6 (1982), pp.3–18.
3. Mills, J. S. and White, R., 'Analyses of Paint Media', ‘National Gallery Technical Bulletin’, 7 (1983), p.67.
4. Mills, J. S. and White, R., 'Analyses of Paint Media', ‘National Gallery Technical Bulletin’, 1 (1977), p.57–9.
5. White, R., 'Rembrandt's Paint Medium', in D. Bomford, C. Brown and A. Roy, ‘Art in the Making: Rembrandt’, National Gallery (London 1988), pp.26–9.

Artist	Picture	Date	Sample	Medium	P/S	Oil type	Note	
Rembrandt	Portrait of an 83–year-old Woman
No.775	1634	1. Light fawn background to left of sitter
2. Black paint of dress	Oil

Oil	1.9

1.8	Linseed

Linseed	1	
	Saskia van Uylenburch in Arcadian Costume
No.4930	1635	1. Grey-white of bottom of dress
2. Dark black/brown of foliage, top	Oil

Oil	3.7

1.9	Walnut

Linseed	2	
	The Lamentation over the Dead Christ
No.43	c.1635	1. Warm white impasto, R.H. edge
2. White cloud, by cross, upper L.H. edge
3. Mustard colour, by white shroud
4. Dark brown/black background, R.H. edge	Alkyd

Oil

Oil

Oil	n.a.

5.6

1.8

1.3	Alkyd

Poppyseed
Linseed

Linseed	3	
	Belshazzar's Feast No.6350	1636/8	1. White impasto of robe
2. Yellow impasto of robe trimmings
3. L.H. woman's head-dress, shadow
4. Red dress of R.H. woman	Oil
Oil

Oil

Oil	1.6
1.7

1.8

1.8	Linseed
Linseed

Linseed

Linseed	4	
	Self Portrait at the Age of34
No.672	1640	1. Light brown parapet, R. H. side	Oil	3.3	Walnut		
	The Woman taken in Adultery
No.45	1644	1. Black impasto, top of centre column
2. Pale orange-brown of R.H. column
3. Ground
4. Red drape, top R.H. edge	Oil

Oil

Oil
Oil	1.6

1.8

1.4
1.9	Linseed

Linseed

Linseed
Linseed		
	The Adoration of the Shepherds
No.47	1646	1. Black background
2. Ground
3. Mustard highlight of roof beam, L.H. edge	Oil
Oil
Oil
	1.1
1.6
1.1	Linseed
Linseed
Linseed		
	A Franciscan Friar No.166	c.1655	1. Brown habit
2. Pale buff paint, top edge
3. Grey-blue background	Oil
Oil

Oil	1.3
3.0
1.3	Linseed
Walnut
Linseed		
	Portrait of Hendrickje Stoffels
No.6432	c.1656	1. White highlight of robe
2. Red background	Oil
Oil	3.3
3.1	Walnut
Walnut	5	
	A Bearded Man in a Cap
No.190	1657	1. Black coat
2. Ground	Oil
Oil	2.7
3.5	Walnut
Walnut		
	An Elderly Man as Saint Paul
No.243	1659	1. Black sleeve of robe
2. Reddish brown, upper R.H. corner	Oil
Oil	1.5
1.7	Linseed
Linseed		
	Portrait of Jacob Trip No. 1674	1661	1. White scarf, right shoulder
2. Reddish brown, side of chair
3. Black, bottom of cane	Oil
Oil
Oil	3.2
1.2
1.8	Walnut
Linseed
Linseed		
	Portrait of Margaretha de Geer
No.1675	1661	1. White ruff
2. Brown background

3. Ground	Oil
Oil + egg?
Oil	1.7

1.6	Linseed

Linseed	6	
	Portrait of Margaretha de Geer, Bust Length
No.5282	1661	1. White impasto
2. Black background	Oil
Oil + resin	1.4
1.5	Linseed
Linseed	7	
	Portrait of Frederik Rihel on Horseback
No.6300	1663	1. White impasto, jacket trimmings
2. Red impasto, cuff trimmings	Oil
Oil	1.8
1.7	Linseed
Linseed	8	
	Self Portrait at the Age of 63
No.221	1669	1. Dark brown, right sleeve
2. Olive-brown background at top edge
3. Ground	Oil

Oil

Oil	1.1

1.6

1.5	Linseed

Linseed

Linseed		
	Judas and the Thirty Pieces of Silver
(Great Britain, private collection)	1629	1. Ground, upper layer
2. Ground, lower layer
3. Black of floor
4. Grey-green background	Oil
Oil
Oil
Oil	1.4
2.1
1.8
2.3	Linseed
Linseed?
Linseed
Walnut	9	
Pesellino	Altarpiece: The Trinity with Saints
No.727	1457	1. Pale blue sky, L.H. edge
2. Green of trees, L.H. edge
3. Warm white of bishop's smock
4. Bright red of R.H. Saint's crimson robe	Egg
Egg + some oil Egg + some oil
Egg + some oil			10	
Nicolas Poussin
Bernardo Cavallino	The Finding of Moses No.6519	1651 1645–50	1. Pale blue sky, L.H. edge
2. Red ground
3. Bright red of female figure's cloak
4. Green, left sleeve of woman receiving Moses	Oil

Oil
Oil

Oil	2.2

1.8
1.8

1.4	Walnut?

Linseed
Linseed

Linseed	11	
	Christ driving the Traders from the Temple
No.4778		1. Black of R.H. figure's robe
2. Brownish ground
3. Dark brown of ledge, architecture, L.H. side
4. Grey-brown, upper L.H. edge	Oil

Oil
Oil

Oil	2.1

2.3
2.1

2.1	Walnut

Walnut
Walnut

Walnut		

National Gallery Publications Limited Published by order of the Trustees

Scientific Adviser, John Mills
Chief Restorer, Martin Wyld
Editor: Ashok Roy

© The National Gallery 1989

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National Gallery
National Gallery technical bulletin. — Volume 13, 1989.
1. Painting — Conservation and restoration — Periodicals
I. Title
751.6'05 ND1640

ISSN 0140–7430
ISBN 0 947645 70 5

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